diff --git a/cpp-linter/src/rest_client.rs b/cpp-linter/src/rest_client.rs
index a6654c03..941dddaf 100644
--- a/cpp-linter/src/rest_client.rs
+++ b/cpp-linter/src/rest_client.rs
@@ -268,46 +268,51 @@ impl RestClient {
             }
             self.show_patch(&feedback_inputs)?;
 
-            let mut options = ReviewOptions {
-                marker: COMMENT_MARKER.to_string(),
-                comments: {
-                    let mut comments = vec![];
-                    for suggestion in &review_comments.comments {
-                        let mut comment = suggestion.as_review_comment();
-                        comment.path = prefix_feedback_path(&comment.path, &self.repo_root_prefix);
-                        comments.push(comment);
-                    }
-                    comments
-                },
-                ..Default::default()
-            };
+            if self.client.is_pr_same_remote() {
+                let mut options = ReviewOptions {
+                    marker: COMMENT_MARKER.to_string(),
+                    comments: {
+                        let mut comments = vec![];
+                        for suggestion in &review_comments.comments {
+                            let mut comment = suggestion.as_review_comment();
+                            comment.path =
+                                prefix_feedback_path(&comment.path, &self.repo_root_prefix);
+                            comments.push(comment);
+                        }
+                        comments
+                    },
+                    ..Default::default()
+                };
 
-            let total_review_comments = options.comments.len() as u32;
-            self.client.cull_pr_reviews(&mut options).await?;
-            let has_changes =
-                review_comments.tool_total > 0 || !review_comments.skipped_fixes.is_empty();
-            let is_lgtm = options.comments.is_empty() && !has_changes;
-            options.action = if feedback_inputs.passive_reviews {
-                ReviewAction::Comment
-            } else if is_lgtm {
-                ReviewAction::Approve
-            } else {
-                ReviewAction::RequestChanges
-            };
-            options.summary = review_comments.summarize(
-                &clang_versions,
-                &options.comments,
-                total_review_comments,
-                summary_only,
-            );
-            if is_lgtm && feedback_inputs.no_lgtm {
-                log::debug!("Not posting an approved review because `no-lgtm` is true");
-            } else if options.comments.is_empty() && total_review_comments > 0 {
-                log::info!(
-                    "All review comments were already posted in previous reviews; not posting a new review."
+                let total_review_comments = options.comments.len() as u32;
+                self.client.cull_pr_reviews(&mut options).await?;
+                let has_changes =
+                    review_comments.tool_total > 0 || !review_comments.skipped_fixes.is_empty();
+                let is_lgtm = options.comments.is_empty() && !has_changes;
+                options.action = if feedback_inputs.passive_reviews {
+                    ReviewAction::Comment
+                } else if is_lgtm {
+                    ReviewAction::Approve
+                } else {
+                    ReviewAction::RequestChanges
+                };
+                options.summary = review_comments.summarize(
+                    &clang_versions,
+                    &options.comments,
+                    total_review_comments,
+                    summary_only,
                 );
+                if is_lgtm && feedback_inputs.no_lgtm {
+                    log::debug!("Not posting an approved review because `no-lgtm` is true");
+                } else if options.comments.is_empty() && total_review_comments > 0 {
+                    log::info!(
+                        "All review comments were already posted in previous reviews; not posting a new review."
+                    );
+                } else {
+                    self.client.post_pr_review(&options).await?;
+                }
             } else {
-                self.client.post_pr_review(&options).await?;
+                log::warn!("PR is from a different remote, skipping review.");
             }
         } else if feedback_inputs.gen_patch {
             for file in files {
@@ -320,6 +325,11 @@ impl RestClient {
         }
 
         if feedback_inputs.thread_comments != ThreadComments::Off {
+            // do not post thread-comments for on PRs from forks
+            if self.client.is_pr_event() && !self.client.is_pr_same_remote() {
+                log::warn!("PR is from a different remote, skipping thread comments.");
+                return Ok(format_checks_failed + tidy_checks_failed);
+            }
             // post thread comment for PR or push event
             if comment.as_ref().is_none_or(|c| c.len() > u16::MAX as usize) {
                 comment = Some(Self::make_comment(
diff --git a/cpp-linter/tests/comments.rs b/cpp-linter/tests/comments.rs
index b4885dfc..13ff3412 100644
--- a/cpp-linter/tests/comments.rs
+++ b/cpp-linter/tests/comments.rs
@@ -45,6 +45,7 @@ struct TestParams {
     pub thread_comments: ThreadComments,
     pub no_lgtm: bool,
     pub force_lgtm: bool,
+    pub is_fork: bool,
     pub fail_get_existing_comments: bool,
     pub fail_dismissal: bool,
     pub fail_posting: bool,
@@ -61,6 +62,7 @@ impl Default for TestParams {
             thread_comments: ThreadComments::On,
             no_lgtm: true,
             force_lgtm: false,
+            is_fork: false,
             fail_get_existing_comments: false,
             fail_dismissal: false,
             fail_posting: false,
@@ -93,6 +95,18 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) {
                     "state": "open",
                     "number": PR,
                     "locked": false,
+                    "head": {
+                        "repo": {
+                            "id": if test_params.is_fork { 200 } else { 100 },
+                            "full_name": if test_params.is_fork { "fork/repo" } else { REPO },
+                        }
+                    },
+                    "base": {
+                        "repo": {
+                            "id": 100,
+                            "full_name": REPO,
+                        }
+                    }
                 }
             })
             .to_string();
@@ -154,7 +168,7 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) {
         }
         mock = mock.create();
         mocks.push(mock);
-    } else {
+    } else if !test_params.is_fork {
         let pr_endpoint = format!("/repos/{REPO}/issues/{PR}/comments");
         for pg in ["1", "2"] {
             let link = if pg == "1" {
@@ -187,7 +201,10 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) {
         }
     );
 
-    if !test_params.fail_get_existing_comments && !test_params.bad_existing_comments {
+    if !test_params.fail_get_existing_comments
+        && !test_params.bad_existing_comments
+        && !test_params.is_fork
+    {
         mocks.push(
             server
                 .mock("DELETE", comment_url.as_str())
@@ -212,7 +229,8 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) {
 
     let lgtm_allowed = !test_params.force_lgtm || !test_params.no_lgtm;
 
-    if test_params.thread_comments == ThreadComments::Update && lgtm_allowed {
+    if test_params.thread_comments == ThreadComments::Update && lgtm_allowed && !test_params.is_fork
+    {
         mocks.push(
             server
                 .mock("PATCH", comment_url.as_str())
@@ -228,6 +246,7 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) {
     if test_params.thread_comments == ThreadComments::On
         && lgtm_allowed
         && !test_params.bad_existing_comments
+        && !test_params.is_fork
     {
         mocks.push(
             server
@@ -252,6 +271,18 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) {
         );
     }
 
+    if test_params.is_fork {
+        mocks.push(
+            server
+                .mock(
+                    "POST",
+                    format!("/repos/{REPO}/issues/{PR}/comments").as_str(),
+                )
+                .expect(0)
+                .create(),
+        );
+    }
+
     // A relative output path is resolved against the working directory (not the repo root).
     // `_out_dir` keeps the directory alive until the test ends.
     let (_out_dir, out_dir_path) = if test_params.relative_out_files {
@@ -566,3 +597,24 @@ async fn relative_out_files() {
     })
     .await;
 }
+
+#[tokio::test]
+async fn new_pr_fork() {
+    test_comment(&TestParams {
+        event_t: EventType::PullRequest,
+        is_fork: true,
+        ..Default::default()
+    })
+    .await;
+}
+
+#[tokio::test]
+async fn update_pr_fork() {
+    test_comment(&TestParams {
+        event_t: EventType::PullRequest,
+        thread_comments: ThreadComments::Update,
+        is_fork: true,
+        ..Default::default()
+    })
+    .await;
+}
diff --git a/cpp-linter/tests/reviews.rs b/cpp-linter/tests/reviews.rs
index f5d7f231..60850c0e 100644
--- a/cpp-linter/tests/reviews.rs
+++ b/cpp-linter/tests/reviews.rs
@@ -36,6 +36,7 @@ struct TestParams {
     pub summary_only: bool,
     pub pr_state: String,
     pub pr_draft: bool,
+    pub is_fork: bool,
     pub fail_dismissal: bool,
     pub fail_get_existing_reviews: bool,
     pub fail_posting: bool,
@@ -56,6 +57,7 @@ impl Default for TestParams {
             summary_only: false,
             pr_state: "open".to_string(),
             pr_draft: false,
+            is_fork: false,
             fail_dismissal: false,
             fail_get_existing_reviews: false,
             fail_posting: false,
@@ -78,6 +80,18 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) ->
                 "state": test_params.pr_state,
                 "number": PR,
                 "locked": false,
+                "head": {
+                    "repo": {
+                        "id": if test_params.is_fork { 200 } else { 100 },
+                        "full_name": if test_params.is_fork { "fork/repo" } else { REPO },
+                    }
+                },
+                "base": {
+                    "repo": {
+                        "id": 100,
+                        "full_name": REPO,
+                    }
+                }
             }
         })
         .to_string()
@@ -129,7 +143,7 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) ->
 
     let reviews_endpoint = format!("/repos/{REPO}/pulls/{PR}/reviews");
 
-    if test_params.pr_state != "closed" && !test_params.bad_pr_info {
+    if test_params.pr_state != "closed" && !test_params.bad_pr_info && !test_params.is_fork {
         let mut mock = server
             .mock("GET", reviews_endpoint.as_str())
             .match_header("Accept", "application/vnd.github.raw+json")
@@ -167,6 +181,7 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) ->
         && !test_params.bad_existing_reviews
         && test_params.pr_state != "closed"
         && !test_params.bad_pr_info
+        && !test_params.is_fork
     {
         // the previous review is outdated (not reused), so it gets dismissed
         mocks.push(
@@ -186,8 +201,8 @@ async fn setup(lib_root: &Path, tmp_dir: &TempDir, test_params: &TestParams) ->
 
     let posted_review = Arc::new(Mutex::new(None));
     let lgtm_allowed = !test_params.force_lgtm || !test_params.no_lgtm;
-    if test_params.previous_review.is_some() {
-        // all suggestions were reused, so a new review is not posted
+    if test_params.previous_review.is_some() || test_params.is_fork {
+        // all suggestions were reused (or is_fork), so a new review is not posted
         mocks.push(
             server
                 .mock("POST", reviews_endpoint.as_str())
@@ -520,3 +535,15 @@ async fn all_suggestions_reused() {
     })
     .await;
 }
+
+#[tokio::test]
+async fn is_fork() {
+    assert!(
+        test_review(&TestParams {
+            is_fork: true,
+            ..Default::default()
+        })
+        .await
+        .is_none()
+    );
+}